ESDU 79009 presents the theoretical basis for three methods available in the literature. All are restricted to isentropic flow and one is further restricted to flows without shocks and thus at transonic speeds to only just-supercritical flows. Of the remaining two, one, strictly, is limited to freestream Mach numbers close to unity but has been adapted to yield useful solutions over a wider range of Mach numbers. The way in which the three techniques are used is described, recommendations are made on the values to be assigned to certain variable parameters within the programs, the range of applicability is indicated, and evaluations made of the programs are discussed. Example solutions of pressure distributions obtained using the programs for specific cases are given graphically and provide valuable test cases for those using the programs for the first time.